Fiber preparation device



Dec. 15, 1953 C, y- MUENCH 2,662,821

FIBER PREPARATION DEVICE Filed May 3, 1949 Patented Dec. 15, 1953 Carl G. Muench, Glenview, lill., assignor t'o Celotex Corporation, Chicago, Ill.,-a-corporation y ofDelaware Appli-tation vMay 3, 1949, 'serai-No. 91,1161

2 Claims. 1

In the paper and allied arts it has long been customary to digest or cook the iibrous material with various chemicals and with very considerable quantities of cooking liquor in closed boilers of one type or another. Lately there has been developed some apparatus and procedure for the preparation of fibrous material in what might be termed a dry process, that is, with but a limited amount of cooking liquor which, in some instances, is present in such a small amount that the brous material is merely moistened, and there is little or no free liquor present.

The present invention relates to an apparatus for pretreating or cooking ber material according to the dry process, that is, wherein normally there is no free liquor, there being utilized only suilicient to meisten the liber material as distinguished from the use of a large amount of cooking liquor to form a flowable pulp.

in particular the invention relates to `a digester wherein the brous material, in but moistened condition, is progressed slowly through a pressure vessel, and wherein the ber is introduced onto a table or shelf-like member and is slowly advanced circumferentially thereon until discharged through an opening in such shelf onto a second shelf, where the procedure repeats followed by the repetition thereof until discharged from the final or lowermost shelf into the bottom of the pressure vessel, whereupon it may be discharged therefrom.

A particular object of the invention is to Y-provide an improved type of apparatus of the character above briefly described, wherein the -construction is simple, the device being so constructed that repairs or renewal of the operating parts are Agreatly simplied, and in particular, wherein the ber material, during its processing within the device, is relatively undisturbed. That is, the fibrous material is cooked or digested Without lqneading or rubbing, or the like, of the material in its relatively raw and unprepared state. Specifically, the objects of theinvention constitute the accomplishment ofk the matters Yjust aforesaid, and include other improvementsand advances which will be apparent to thoseskilled in the art upon reading vthis specification, taken together with the accompanying drawings.

ln the accompanying drawings the vdevice is disclosed in Figure l as substantially a cross-'section of the device taken on line I-I ofFigure 2;

Figure 2, a horizontal cross-section taken on line 2-2 of Figure l, and

Figure 3, a cross-sectiontaken on line 3'-3 of Figure l.

The device constitutes a pressure 74shellfon boiler, ythe body 0fr which ifs 'designated by numeral l0, the tp head "by Il, 'and the bottom 'head tbv l2. Itis understood, of course, that vthe top *and bottom heads Hand `l2,rjejsp'ectively,'are suitably belted together et their nshg'es ils by :means .er bolts 14. Mounted .withnthe pressure shell 'body I0 there is provided 1a v@Sag ithevertic'allarm's'of which are designated Lb'yt numeral l5, 'which vertical arms `clim'riacted by 'topjand botten; `spider portions I6 and IL'jifespectiveIy. The'top spider i6 is separate fromfthe aerticfail s i| 5,`,as 'is clearly apparent in the "drawing, fand may be `secured `thereto by 'suitable icountersukscrews 'or the like, which actual fastening 'means lare vnotv illustrated, #but the ipr` visio. of which will bgereadily apparent to any'mech nic. A i

The top spider arms i6 are-cohnectedito'alc'ollar member I8 Whichis central'with respect thereto, andfromwhi'chthej'spider arms I6"pro ject radially. lIt Willgbe understood, ofcourse, that the spider "arms `ankd'vertical arm members l5 are not limited te 4threeonly,but there may be provided two such or four or five or any other practical number, vas these portions constitute merely a skeleton .or frame to which the vother portions `of the internal structure of thedevice are connectedl or Orl .whichfthey fare mounted.A

Centrally, the lowervspider arms Il merge finto a central collar or'bearing-f. y Y

The shell portion l0 ofthe ldevice is provided around its periphery, intern-any, V,with lsuite-hie recesses 25 to receive'the verticalarms |'5 ofthe cage, and it will `be .understoodof course, that the number of theserecesses 25 "provided :correspond rto the number of vertical 4arms of Ywhich the cage portioniscomposed. "I'he side walls'of these recesses 2 5 compriselabutments which restrain rotation of the 'cage member dueto ,the restraining effect with Y.respect `to the vertical arms 'l5 l`of the cagemember.

Suitablyjmounted .inlthe cagamember and `se cured to the vertical arms -.5'.thereareshelfor table members .26 which are circular members, each having a,cutoutraswi1lbehereinafter de'- scribed. These shelf members 26y aresUitabIysecured to thevertical yanios f l--as by welding, crit is readily understood they may, be ,secured thereto in any desired manner. {Ihesegshelfmembers 26 are e spaced-,apartverticallyqa distance which, of course, will be flargely Va fmatter -of design, that is, they will be .spaced :sufficiently to accommodate the amount of ber materialwhichl is tot befhand-ledf and :will be.l provided in suicient number f to provida in conj unction with @the ,-othered'esig'ned =felements, ifor the #idesired time interval of progression of the fiber material through the device. Merely as an example, it may be taken that the device is provided with five of the table members 26 spaced vertically, one from another, 12 inches. As will be readily understood from the entire description, the number of the table members and spacing, as referred to, is merely arbitrarily taken, and in actual practice it will be more likely that there will be something like 20 of the table members 26 with approximately six inch spacing.

In the head portion I I of the shell there is provided a bearing and seal 21 in which may be mounted shaft 28, on which shaft 28, immediately above each of the shelves 26, there is mounted a member 25 having radial arms 30, and which is pinned to shaft 28 by a pin 3l or the equivalent.

Also provided in the head portion II of the shell there is a liber supply device 35 for supplying moist fiber and discharging it upon the topmost table 26 within the shell. This fiber supply device may be a pressure screw 36 operating within the supply conduit 35, or may be any other suitable device for feeding the fiber into the device against steam pressure maintained therein.

For rotating shaft 28 there may be provided a gear 40, and for the introduction of suitable chemicals, water if desired, and steam, there may be provided chemical supply piping 4I, steam supply piping 42 and water supply piping 43, each suitably secured in the shell head I I. At the bottom of the device, and forming a part of or secured in the shell body I2, there is provided a discharge conduit 44 in which there may be a valve 45, and also suitably mounted to said shell bottom I2 there are provided water jet nozzles 46 supplied by piping 41.

Discharge valve 45 is a vane or measuring valve which discharges the pulp stock from the digester at substantially atmospheric pressure while retaining full pressure in the digester. Valve 45 comprises a cylindrical body in which mounted on shaft I there are provided radial vanes 52 between which are formed pulp receiving pockets. The valve may be operated at the required speed by gear 53 mounted on shaft 5 I. In operation the spaces between the vanes fill with the pulp stock from the digester and as the valve rotates, these charges are successively discharged, as is readily apparent in the drawing. The specific valve construction is shown only as an example, and any equivalent throttling or pressure retaining discharge device may be employed.

According to the specific disclosure hereof, and since each of the sets of radial rotating arms 33, operating in cooperation with and with respect to shelf members 26, is provided with six equally spaced radial arms which are thus 60 degrees apart, it results that the openings or cut-out portions of the shelf members 26 are approximately a 60 degree segment of a circle, and that the successive openings in the respective shelves 26, considered downwardly, are positioned, displaced, 60 degrees with respect to their respective edges in a direction counterclockwise with respect to the opening through the shelf member 26 immediately above. It will thus be seen that fiber material discharged into one -of the radial segments will be carried around between a pair of radial arms 30 until it comes to an opening through shelf 26, whereupon the fiber material will discharge through the opening under ythe influence of gravity and will fall upon shelf 26 immediately below, and will be received thereon between a pair of radial arms 30 cooperating therewith. This, of course,- assumes that `shaft;

28 and radial arms 3D mounted thereon are rotated in clockwise direction, and it will be understood, of course, that should the rotation be in reverse direction, that the respective openings through the shelf members 26, going downwardly through .the device, will be displaced in a clockwise direction.

As the fiber material from the topmost shelf is discharged onto the next lower shelf member 26, it will be received between a pair of cooperating radial arms 3o and carried around and discharged through the opening in the second shelf, and thence serially likewise the fibrous material will be discharged through an opening through each next succeeding shelf member 26, and carried around on the shelf between a pair of cooperating radial arms 30 until finally this fibrous material is discharged from the opening through the lowermost shelf member 26 to the bottom portion of the shell. The fiber, when discharged from the lowermost shelf member 26 into the shell bottom I2, may be diluted to a flowable consistency by water introduced under pressure through jet nozzles 46, and this flowable pulp may then flow out of the device through the discharge conduit member 44.

Any suitable digesting chemical may be supplied to the fiber as it enters the device, or may be supplied to the ber material as it is received on the top most shelf member 25, such being introduced under pressure through piping 4I. The type of digesting chemical or amount thereof will, of course, depend on the type of raw liber material supplied and the type of and extent of digestion to be carried out within the device. The chemical supplied may be an ordinary caustic cooking liquor, or may be in the nature of a kraft liquor, or a sulphite or modied sulphite liquor or the like, it being understood, of course, that such is supplied in a relatively concentrated form so that, as previously referred to, the fiber material is only moistened or wetted and is not in any sense of the word a pulp as such is ordinarily considered, but it is merely a mass of dampened ber. Steam pressure, as desired to accomplish the amount cf cooking or digesting required with the specic chemical added, is maintained by means of steam introduced through piping 42 and, if desired, additional water may be introduced through piping 43, or water may be introduced through this piping for washing out the device when such is desired.

It will be seen that ber material may be digested in the device hereof according to any predetermined procedure, and that dependent upon the speed of rotation of the shaft 28 and number of shelves 26 and cooperating radial arms 36, the fiber may be subjected to any period of digestion desired. In this device the ber material is not rubbed, kneaded or otherwise worked during the period of its digestion. It is merely carried slowly through the device in a substantially quiescent condition except for the gentle tumbling, mixing action which occurs as the masses are discharged from one level to the next lower level, merely falling by gravity, and Vthus the non-fibrous lignins and the like may be chemically acted upon without subjecting the fibrous substance, while relatively brittle, to deleterious mechanical action, so that the resulting digested fiber material comprises uninjured fibers with the lignins and the like disintegrated or digested to such extent as is desired, depending upon the specific digestion process to which the material has been subjected.

A particular advantageous feature of the construction disclosed is that for repairs or overhauling the entire interior operating portion of the device is readily removable, as it is only necessary to remove the bolts or the like securing head II to the shell I0, and then the entire interior assembly may be withdrawn from the shell. After withdrawal of the interior assembly from the shell, upon removal of the securing pins or the like, 3| securing radial arm members to the shaft, then shaft 28 may be withdrawn and the various radial arm members may be removed and the entire interior construction is readily accessible for cleaningI or renewal or the like.

The construction of the device hereof and the operation thereof having been above fully disclosed, what I claim is:

1. A digester construction comprising a housing shell, top and bottom heads therefor, one of such heads removably mounted to and secured to the shell, a removable assembly mounted in the housing shell, the removable assembly comprising an elongated unitary cage member, central shaft bearings mounted to the unitary cage member centrally thereof at each end, spaced shelf members mounted to the cage member, a central shaft carried by the cage member and mounted in said shaft bearings, groups of spaced substantially radial arms mounted in spaced relation along and to the shaft and positioned thereon to sweep over the upper surface of each of the shelf members, each shelf member having a segmental opening therethrough and of configuration and dimensions substantially that of the area encompassed between adjacent substantially radial arms of a group thereof, the openings in the shelf members circumferentially offset with respect to such openings in adjacent shelves by an amount substantially equal to the width of a such opening, the shell interiorly thereof providing abutment surfaces and the such abutment surfaces and portions of the unitary cage member engaging and restraining relative rotation of the cage member with respect to the shell.

2. A digester construction comprising a housing shell, top and bottom heads therefor, one of such heads removably mounted to and secured to 6 the shell, a removable assembly mounted in the housing shell, the removable assembly comprising circumferentially spaced vertical elongated arm members and spider members, the vertical elongated arm members at their opposite ends secured to the spider members comprising a central shaft bearing and radially extending arms and constituting a unitary cage construction, spaced circular shelf members mounted at their edges to the vertical arms of the cage construction, a central shaft carried by the cage member and mounted in said shaft bearings, groups of spaced substantially radial arms mounted in spaced relation along and to the shaft and positioned thereon to sweep over the upper surface of each of the shelf members, each shelf member having a segmental opening therethrough and of configuration and dimensions substantially that of the area encompassed between adjacent substantially radial arms of a group thereof, the openings in the shelf members circumferentially offset with respect to such openings in adjacent shelves by an amount substantially equal to the width of a such opening, grooves in the shell, opening to the interior thereof and receiving the vertical arm members of the cage construction and in cooperation thereof restraining relative rotation of the cage member with respect to the shell.

CARL G. MUENCH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 113,502 Denis Apr. 11, 1871 241,653 Harrison May 17, 1881 439,032 Forbes Oct. 21, 1890 879,842 Swart Feb. 18, 1908 1,036,486 Guignard et a1 Aug. 20, 1912 1,556,927 Fritz Oct. 13, 1925 1,757,616 Bunce May 6, 1930 1,794,214 Thurm et a1 Feb. 24, 1931 1,827,7 10 Leyest-Kuchenmeister Oct. 13, 1931 1,863,109 Graves June 14, 1932 2,134,229 Lipscomb Oct. 25, 1938 2,166,351 Hagen July 18, 1939 

1. A DIGESTER CONSTRUCTING COMPRSING A HOUSING SHELL, TOP AND BOTTOM HEADS THEREFOR, ONE OF SUCH HEADS REMOVADLY MOUNTED TO AND SECURED TO THE SHELL, A REMOVABLE ASSEMBLY MOUNMTED IN THE HOUSING SHELL, THE REMOVABLE ASSEMBLY COMPRISING AN ELONGATED UNITARY CAGE MEMBER, CENTRAL SHAFT BEARING MOUNTED TO THE UNITARY CAGE MEMBER CENTRALLY THEREOF AT EACH END, SPACED SHELF MEMBERS MOUNTED TO THE CAGE MEMBER, A CENTRAL SHAFT CARRIED BY THE CAGE MEMBER AND MOUNTED IN SAID SHAFT BEARINGS, GROUPS OF SPACED SUBSTANTIALLY RADIAL ARM MOUNTED IN SPACED RELATION ALONG AND TO THE SHAFT AND POSITIONED THEREON TO SWEEP OVER THE UPPER SURFACE OF EACH OF THE SHELF MEMBERS, EACH SHELL MEMBER HAVING A SEGMENTAL OPENING THERETHROUGH AND A CONFIGURATION AND DIMENSIONS SUBSTANTIALLY THAT OF THE AREA ENCOMPASSED 